docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          assert all(stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
                     for stddev_type in stddev_types)
  
          C = self.COEFFS[imt]
          mag = self._convert_magnitude(rup.mag)
  
          mean = (
              C['c1'] + C['c2'] * mag + C['c10'] * (mag - 6) ** 2 +
              (C['c6'] + C['c7'] * mag) * np.log(dists.rjb + np.exp(C['c4']))
          )
          mean = clip_mean(imt, mean)
  
          stddevs = self._compute_stddevs(C, dists.rjb.size, stddev_types)
  
          return mean, stddevs